Design of 2-Axis Cartesian Gantry Robot for Connecting Rod Handling in Final Gauging and Grading Application

Transcription

1 Design of 2-Axis Cartesian Gantry Robot for Connecting Rod Handling in Final Gauging and Grading Application Mugdha Phadtare 1, Renukalaxmi Dudhe 2, Snehal Shitole 3, A.M.Ekatpure 4 1 Miss, Mechanical Engineering, SKNCOE, mugdha162@gmail.com 2 Miss, Mechanical Engineering, SKNCOE, 27renu27@gmail.com 3 Miss, Mechanical Engineering, SKNCOE, snehal.shitole1@gmail.com 4 Prof, Mechanical Engineering, SKNCOE, ekatpureashishm@sinhgad.edu ABSTRACT The purpose of this project is to understand factory automation for certain applications for inspection and grading of connecting rods. Grading of connecting rods is done using automated in-process verification. Automation is necessary for fool-proofing of checking quality parameters and to eliminate human intervention to avoid errors and subsequent degradation of quality. Connecting rods are graded and similar grades are used in an application to ensure uniformity. The parameters on the basis of which connecting rods are graded are center-distance, diameters of big-end and small-end, thickness at big-end and small-end and weight. Gantry robot is designed on the basis of various parameters such as number of axes in which motion is permitted, motion profile, stroke length of set-up in those directions, type of gripper used, cycle time defined by customer, guiding system, selection of transmission elements, motor, sensors, encoders, gear box, input-output systems, safety interlocks, geometrical dimensioning and tolerance. Making use of the above elements, grading of a connecting rod is carried out within the prescribed time given by the customer. Keywords: Automation, Connecting rods, Gauging, Grading, IPV, Gantry robot INTRODUCTION Automation can be perceived as an intended, collaborative and efficient use of machines, control system and information technology to achieve productivity, repeatable quality and reliable performance in various manufacturing processes. It also takes out operator from the tasks and hence eliminates the dependency on skill of an operator. Categories of automation on the basis of quantity and variation: 1. Fixed (Hard) 2. Flexible 3. Programmable (Soft) Category of this project- flexible automation Classification on the basis of function: 1. Continuous process 2. Manufacturing 3. Factory Some elements of the firm s production system are likely to be automated, whereas others will be operated manually or clerically.[1] For our purposes here, automation can be defined as a technology concerned with the application of mechanical, electronic, and computer-based systems to operate and control production.[1] The automated elements of the production system can be separated into two categories: (1) automation of the manufacturing systems in the factory and (2) computerization of the manufacturing support systems.[1] In modern production systems, the two categories overlap to some extent, because the automated manufacturing systems operating on the factory floor are themselves often implemented by computer systems and connected to the computerized manufacturing support systems and management information system operating at the plant and 527

2 enterprise levels.[1] The term computer-integrated manufacturing is used to indicate this extensive use of computers in production systems.[1] Fig-1: Types of Automation Types of factory automation- Handling and assembly automation Category of this project- handling automation with in-process verification or inspection in production line. Material Handling and Storage. A means of moving and storing materials between processing and/or assembly operations is usually required.[1] In most manufacturing plants, materials spend more time being moved and stored than being processed.[1] In some cases, the majority of the labor cost in the factory is consumed in handling, moving, and storing materials.[1] Inspection and Test. Inspection and test are quality control activities.[1] The purpose of inspection is to determine whether the manufactured product meets the established design standards and specifications.[1] 1.1 Problem Statement Design of 2 axis cartesian gantry robot for connecting rod handling in final gauging and grading application. 1.2 Need Need of this project is to understand factory automation for certain applications for inspection and grading of connecting rods. In-process verification (IPV) of quality of connecting rods is to be done in order to reduce the number of rejects. Automation ensures full-proofing of checking quality parameters, it also helps to eliminate human intervention. Grading of connecting rods on the basis of parameters like centre-distance and mass so that those having similar specifications can be grouped together and used in the applications. Automation induces a safe working environment. Connecting rod is often in high speed movement as one of the main parts of automobile engine.[2] It s shape error and accuracy of the hole or the plane will directly influence the working performance and the service life of engine.[2] So the production has very strict requirements on the shape error.[2] Connecting rod standard gauge block, as a standard part of manufacturing connecting rod, it s manufacturing accuracy is higher, and the measurement and calibration of error directly affects the machining efficiency and the precision of the connecting rod.[2] 1.3 Objective To design a gantry robot for handling connecting rod To design work stations to: 1. Measure parameters like mass and centre distance between big end and small end of connecting rod 2. Set up a traceability system by using 2-D matrix to be marked by dot marking machine 3. Sorting of OK and NOT OK components as well as grading of the same 528

3 2. LITERATURE REVIEW Vision inspection plays an instrumental role in factory automation. In the past, manufacturers struggled between relying either on a team of operators to manually inspect parts for defects or on an expensive early generation automated vision system. On the one hand, manual inspection could never match the accuracy of an automated vision system. Inspection operators would get tired and inspection quality gradually suffered further into their shifts. On the other hand, an early vision system was expensive and did not have the hardware capabilities to handle the more complex algorithms that were required. The industry has changed a lot since then, as vision hardware and software capabilities have improved dramatically while equipment cost has lowered to the point where it now makes sense to automate visual inspection.[3] Machine vision systems in factory automation seldom operate in a stand-alone mode. Instead, they send information to other parts of the factory enterprise for a variety of purposes. Quality traceability, for instance, requires the vision system either log or report inspection results to the enterprise.[3] 3. METHODOLOGY Requirement of customer Conception of model Design calculations of- - Motion Profile Technical study of automation - Cycle Time -Guiding system -Motor -Gearbox - Transmission Elements Selection of- Machine manufacturing - Gripper Final machine design Drawings of machine on AutoCad, Solid Edge, BricsCAD Pro A A - Encoder - Sensor RTrial 1 Inspection of machine Trial 2 Rectification and improvement Approval 529

4 4. DESIGN Number of axes Stroke length Type of motion Motion Profile Cycle Time Selection of Transmission Elements Encoder Gripper Sensor Fig-2: Proposed view of structure Cycle Time: calculated by 1. Triangular motion planning 2. Trapezoidal Motion Planning PARAMETER TRIANGULAR TRAPEZOIDAL s (DISTANCE) at²/4 2(ta³) t (TIME) (4s/a)^(½) 3(s/2a)^(½) a (ACCELERATION) 4s/t² 4.5s/t² v (max VELOCITY) 2s/t 1.5s/t Table-1: Formulae for cycle time calculation As per our calculations, cycle time is found to be 30 seconds Transmission elements used: Transmission elements can be chosen as rope, chain, timer belt or rack and pinion. 530

5 Choice of Drive Speed Accuracy/ Backlash Efficiency Choice mechanism Precision Rope Friction Moderate Low No High Chain Positive Moderate Low Yes High Timer Belt Positive High High No High Rack & Pinion Positive High High Can be High either 5. EXPERIMENTAL VALIDATION Stroke Length in X-direction: 4.14 m Stroke Length in Z-direction: 0.35 m Type of Motion: Linear in X and Z directions Motor manufactured by: MITSUBISHI ELECTRIC Series of the motor : HG-SN 102 J[5] Gripper manufactured by: FESTO Material of gripper :Brass Inductive Proximity: 15 Capacitive Proximity: 7 Area Sensors: 2 Float Sensors: 2 Sensors manufactured by: BALLUFF Drag Chain: It is used for cable management. Manufacturing company: IGUS Bins: Number of bins-7 Number of connecting rods in each bin:10 Outer dimension of bin: (0.4*0.3*0.22)m Inner dimension of bin: (0.375*0.274*0.195)m Table-2: Selection of Transmission Elements 6. CONCLUSION Hence, we designed 2 axis cartesian gantry robot for connecting rod handling in final gauging and grading application. The cycle time was within the prescribed time by the customer. ACKNOWLEDGEMENT We would like to take this opportunity to express our honour, respect, deep gratitude and genuine regard to our industry guide Mr. Rajendra Nisal, Director of Penta Designers & Engineers, Pvt. Ltd. It is my pleasure to acknowledge sense of gratitude to Dr. A.P.Pandhare our Head of Department and Principal Dr. A.V.Deshpande for their great support and encouragement during our project. Finally yet importantly we would like to thank all Staff Members and all our colleagues for their valuable suggestions and support. REFERENCES [1] David O'Sullivan, "Industrial Automation", May [2] Wei Min Pan, Ning Ning Kong, Xin Ye, "Precision Measurement and Error Evaluation of Connecting Rod Standard Gauge Block Based on CMM", Scientific.Net, Vol. 620, , August [3] Richard Lum, "Introduction to Inspection", Cubatic Technology, June [4] Steve Geraghty, Carmen Ciardiello, "Factory Automation Systems in sight", International Society of Automation Publications, June [5] 531